Diethylstilbestrol DES Exposure in Utero

Last Modified: April 27, 2008

Dear OncoLink "Ask The Experts,"

I am a 31 year-old confirmed DES [-exposed] daughter. Are there any guidelines for my physicians to follow? I have had low-grade abnormal paps (CIN1 & VAIN1) a few times now and the most recent was VAIN2.

Christina S. Chu, MD, Assistant Professor of the Division of Gynecologic Oncology at the University of Pennsylvania Health System, responds:

Diethylstilbestrol (DES) was prescribed to prevent spontaneous abortion and premature delivery in the U.S. between 1938 and 1971. In the 1970's, it was discovered that DES was related to an increased incidence of clear-cell adenocarcinoma of the vagina and cervix. The incidence of this is still very low (about 1-1.5 in every 1000 DES daughters), but represents a real risk. Approximately half of all patients with clear cell carcinomas of the cervix and vagina have a history of exposure in uteroto DES. The median age at which these cancers are diagnosed is in the early 20's, but cases have been reported in the 30s and 40s. The risk is greatest when the mother was given DES during the first trimester. The incidence of intraepithelial neoplasia was double the rate in the normal non-exposed population. In studies following exposed women, the average age is still less than 40, so it is not known if there will be any increased risk for this or other cancers as these women age.

In general, pregnant patients were not prescribed DES after 1971 in the U.S., when the FDA made its announcement regarding links from DES to various problems, but it was used in other countries. However, if you believe that you were exposed, even though you were born after this time period, it is good that you have had appropriate screening. In your case, it is impossible to say whether your cervical and vaginal dysplasia is due purely to DES exposure as a fetus, or whether it is due to a particular strain of HPV.

DES-exposed daughters should undergo yearly pelvic exam including examination of the rectal area. The physician should feel the pelvic organs for any lumps, which may be an indication of an abnormal growth. As part of a pelvic exam, the doctor feels the vagina, uterus, cervix and ovaries for any lumps.

In addition to a routine yearly cervical Pap test, patients should have a "four-quadrant Pap test" which tests cells from all sides of the vagina.

Your physician may examine the vagina after temporarily staining it with an iodine solution to help find areas of adenosis (an abnormal but benign growth of glandular cells).

Any abnormal Pap tests should be evaluated with colposcopic examination and directed biopsies.